Locomotive draft appliance.



D. M. LEWIS.

LOCMTiVE DRAF APPLIANCE.

APPLICATION man MM. az. um.:

Patented Oct. 29, 1918.

l i t l" s i r ATTORNEY..

UNITED sTATEs PATENT oEEIcEn DAVID M. LEWIS, or TorEm, Kansas, AssIeNonor Two-Trims To JOSEPH 15. rUncELL, or cIIIcaeo, ILLINOIS.

LOCOMOTIVE DRAFT APPLIANCE.

Bpeoication of Letters Patent.

lineman ma. 29.1918.

lTo all fwhom it ma concern.'

Be it known t at I, DAVID `M. LEWIS, a citizen of the United States,residing at Topeka, in the county of Shawnee, State of Kansas, haveinvented certain new and useful Improvements in Locomotive DraftApliances, of which the following is a specication.

The first ofthe objects of m present invention is to overcome in a sustantial degree the strains upon the tubes or iiues and the iiue sheetwhich are incident to the present ordinary or standard design of draftapparatus in which ,the draft effect iform of nozzle 7 correspondi ofthe nozzle is unevenl distributed, as

a result of which, with t e standard con-y struction, the center iiuesare generally overworked, that is," carr the major portion of theproducts of com ustion, while the fines' at `the sides, especially thoseat the extreme margins, have less draft andere not worked to capacity.

Another object of my resent invention is to secure an increase in t eboiler capacity and greater eiiiciency in operation as well as todecrease the fuel consum tion required to erforln a ven amount o work.

nother obJect of :ny/improved draft appliance is to provideaconstruction in which or a given amount of, tptaldraft action "upon aboiler, a larger nozzle opening may he used, resultin in reduced backpressure. Still another o ject of my lnvention 1s the provision of animproved means for y "securing accurate adjustmentiofthe nozzleopenndther object of 'my inventan isole provision of means for mamtammga more uniform or constant condition of vacuum in las may hereinafter athefiillmt end and consequently more yeven my improvementsapplied'thereto;.Fig,2' A` an end View of the apparatus shownlinlEig. 1,with thefront plate of thesmoke borremoved; and Fig. 3 is a sectionalview taken on the line III-III of Fig. 1. ,f l Referring now to Fig. 1,it will be yaaien that I have therein shown a stack 4 at lts lower end aiared ortionf 5, theontire stack being substantie. ly rectangular. orelongated in section transversel of` the smo e box, the width beingmaciza to correspond as nearly as possible with the width of the fluesheet indicated at 6. f,

Below the stack I provide an improved y in 'ener-al. shape with thewidened or ex end stack and composed primaril of a casing 8 havingtherein two relative y movable members 9 that are locked in place by setscrewslO 70 and which may be adJusted in position relative to cach othertovary the nozzle opening by means of the adjusting screws 11. Theslotted aperture forming the nozzle opening between the two members 9 ispreferably arranged as shown, of a double wedge shape, the walls of theupper w dgepart flaring outwardly as indicated at fcct'of theintermittent exhaust discharges from the cylinders, thisheingaccomplished b leadin gthe `exhaust steam .-utpwarfvlcs` tlirough t epassage 14 which disc es n ear the center 'of the expansionchani r andoonnect -he expansion chambengat either side by he pipes 15 totheapertui'es 90 16 l'and 17 in the base ofthe nozalelcasingoor box 8, nFrom the above description it will lie-seen that with the laterallyspread nozzlewhich I em loy, I will secure a draft eliectwhiehat will hemnchuxiore evenly spread oveugthe entire width of the iiuef Sheetwhiohwill serve to decrease the relative workoutils` center iiues andforce the side'iuesto carry more nearly their proportion of hot gases,thus insuring a more-uniform wear `upol` al1 the dues and avoiding thenecessity so' common in present practice of more fre quent renewal ofthe center flues.

It will be further a )parent from the above description that by t earrangement shown, 1 have to a considerable extent overcome thedifiiculties due to the pulsating or inter niittent draft socharacteristic o' the action of the present devices at slow workingspeeds at which, in sonic cases, with the ordinary form of nozzle, thereis at certain periods of time almost a complete absence of vacuum in thefront end which means that between exhausts, that is, four times in eachrevolution, there is practically no movement of the products ofcombustion through the fiues. The operation just re4 ferred to ascharacteristic of thc common construction causes the flucs, especiallythose in the center, to become heated very much higher during the timethe blast of the nozzle is effective, the water .surrounding them havingcooled them substantially in the in` terval when the vacuum was notoperative, the result being that the fines are continually undergoing :irapid expansion and contraction which tends to work theni loose in thesheet, resulting in leakage and engine failures.

By,1;arrying the exhaust from the cylinders into the expansion chamber13 through a large pipe 14 and then allowing the eX- haust to reach thenozzle through the two small pipes l5, a more nearly uniform effect ofthe blast is secured and while upon the initial discharge for any givenexhaust there will be of course less forcible expulsion of the steam,the equalization obtained will more than compensate in the beneficialac` tion secured upon the ilues. The presence of the expansion chamber13 will also have the effect of allowing the cylinder pressure to dropmore quickly than in the present arn rangement where it Works against achoked or restricted nozzle. That is to say, by utilizing a `large sizedpipe 14, the exhaust steam from t e cylinders is permitted to flowfreely into the expansion chamber from which latter there will be thenobtained a more sustained or prolonged and approximately uniform blast.Thus while there will be an intermittent discharge from the cylindersinto the receiver,` this will take place With greater freedom because ofthe lesser degree of obstruction and the escape from the receiver willbe more continuous and uniform, and the receiver being at all times opento the nozzle, will aid in reducing the cylinder back-pressure evenalthou h the nozzle a'rea were to be left substantial y the same as inthe present standard design. During the interval when the engine valvesare closed, the nozzle in my construction will receive pressuredischarge from the receiver which will produce the substantiallycontinuous flow referred tol The receiver or expansion chamber andnozzle in my construction should be so ioportioiied as to not allow thestack dra vt to cease entirely even at slow speeds, whereby any tendencythere might be l'oi air io work downward tlirou rh the stack and destroythe vacuum in the 'ront end will be obviatcd. lVitli the present design,when an engine is movin r slowly, the front end often partly filled )ythe atmospheric pressure entering the slack between exhausts, which notonly destroys the vacuum in the front end and stops the passage ofheated gases through the fines, allowing the latter to be unduly cooledby the water, but forces a large proiportion of the next exhaust to douseless work in displacing the pressure in the` front end before therequired vacuum can be re created. In my construction by the provisionof the substantially constant draft above described, I` insure that thefront end` cannot be filled from any' place except the fire box which otcourse pi'odums a steady and efficient draft through the fire box,maintaining a more constant temperature in both the fire box and fines.

Another advantageous result of my eiin tended or widened nozzle andstack is due to the ell'ect upon the fire of more eiiicient action andbettei distribution of the heat through the fines. That is to say, bymore fully utilizing the capacity of the side tubes or lues, there isobtained a better distribir tion of the draft upon the fire itself.

That the arrangement above described will secure a marked decrease infuel conv suinption as com :tred with present devices will be evidenturther from the fact that Where the flow of' gases, as in the present}pparatus, is too rapid in the tenter flues, t iere is not sufiicienttime for proper radio tion of the heat to the Water. Thus a moreconstant flow, such as I obtain, Without tlm extreme fluctuationsbetween rapid and no How, will be much more effective. Furthermore in myarrangement there will be a more efiicient effect produced from the sidesheets because the greater draft through the side tubes or flucs willsecure a better fire at the sides of the fire. Another advantage of myarrangement will be that less unburned fue] will be pulled out of thefire box than is the case with present devices in which the heavy draftoccurring intermittently during exhaust frequently wastes considerablecoal.

/Still another result will be that in my conbe made therefrom withoutdepartin from the s irit of the invention as herein efined.

I c aim: The combination with a locomotive having a smoke box and n Huesheet, of :i draft appliance comprising a flattened stack of a Widthcorresponding substantially to the Width of the group of lines inthey'lue sheet,

and a flattened n ozzle coperating with said ack and having a widthcorresponding to 10 the width of the stack,

the major axes of the stuck und nozzle being transverse of the smokebox.

In testinxony slgned my name.

whereof I have hereunto DAVID M. LEWIS.

